SETI Seeks Ideas to Hunt Strange Alien Lifeforms — **The SETI Institute's Allen Telescope Array in California seeks out radio transmissions from hypothetical aliens. Is there another way?**
**Credit: Colby Gutierrez-Kraybill/Wikimedia Commons**

In one of Carl Sagan's last books, he noted that astronomy has brought humanity to a series of "great demotions." Simply put: When we first observed the night sky, we thought the Earth was in the center of the universe. Over time, as he described in Pale Blue Dot, we tried out other theories as the criteria fit: Maybe the sun is at the center of the universe? Perhaps we're in an important part of the galaxy?

We now know the Earth is in the suburbs of the Milky Way, and our solar system is only special because we live in it, but this series of demotions shows us one thing: it's easy to project our image on to the universe. This is especially true when searching for life. Because there is only one case of life as we know it — life on Earth — it's easiest to look for life like ours. But in reality our kind of life may not be the most common type to look for after all.

A new paper in Astrobiology is asking the astronomy community to help the SETI Institute. (SETI stands for "Search for Extraterrestrial Intelligence.") With more data on exoplanets coming in from the Kepler space telescope, and 50 years of space and SETI observations behind us, the hope is new tools can emerge to improve the search for life.

"A key concept is the one of cohabitation of life and environment ... Each planet is a unique planetary experiment, and if we are starting to model these environments, then we can start to figure out what kind of diversity is out there," author Nathalie Cabrol, the SETI Institute's senior research scientist and director of the Carl Sagan Center, told Discovery News.

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One example she suggests in her paper is looking for an element that is in disequilibrium in a planet's atmosphere. (In other words, if scientists see a lot of silicon in an atmosphere that physics predicts would have little, perhaps that could show silicon-based life there.) The advantage is the aliens wouldn't necessarily have to be sending out signals for us to find, she added.

A recent blog post from the SETI Institute's Seth Shostak highlighted this fact for Earth, pointing out our oxygen signature has broadcast life for more than two billion years.

Indeed, much of astrobiology itself is built on assumptions. Scientists commonly speak of a "habitable zone" for planets, based mostly on where Earth is located in our own solar system. Exoplanet biology is also compared with our own, such as when instruments for Mars are tested here based on their abilities to find Earth microbes.

Radio and optical searches, she added, are still the best tool we know of for searching given our known physics of the universe. But she does point out in the paper that the SETI Institute has been focused on the endpoint of the famous Drake equation — how many communicating civilizations there are — rather than "trying to understand or quantify the processes taking place within each of the factors's [for life] that lead to the next."

Even Frank Drake himself, she added, said his equation was not aimed to look for microbes or non-communicating species.

Cabrol said the goal of her paper — which she emphasized is just a single data point, open to discussion and dispute from other astronomers — is not to necessarily say these ideas are wrong. Instead, her hope is that after the SETI Institute organizes a workshop next year to explore these issues, that astronomers may have a better idea about where to point their telescopes.

Originally published on Discovery News.

{ http://www.space.com/ }

A12

It is becoming very clear that us humans may not be not the universe’s first advanced civilization.

This is the conclusion of a recent revision of the famous 1961 Drake Equation, which actually estimates the number of intelligent civilizations in the universe.

Their new equation includes recent data from Nasa’s Kepler satellite on the number of exoplanets that could harbour life.

Researchers also adapted the equation from being about the number of civilizations that exist now, to being about the probability of civilization being the only one that has ever existed!

We are FAR from alone

This important recent study shows that unless the odds of advanced life evolving on a habitable planet are astonishingly low, then humankind is not the only advanced civilization to have lived and there are probably far more advanced Beings out there in the greater Universe!

In fact, the odds of an advanced civilization developing need to be less than one in 10 billion trillion for humans to be the only intelligent life in the universe.

But Kepler data places those odds much higher, which means technologically advanced aliens are likely to have existed at some point.

Adam Frank, professor of physics and astronomy at the University of Rochester and co-author of the paper, went on to say:

‘The question of whether advanced civilizations exist elsewhere in the universe has always been vexed with three large uncertainties in the Drake equation,’

‘We’ve known for a long time approximately how many stars exist.

‘We didn’t know how many of those stars had planets that could potentially harbour life, how often life might evolve and lead to intelligent beings, and how long any civilizations might last before becoming extinct.’

‘Thanks to Nasa’s Kepler satellite and other searches, we now know that roughly one-fifth of stars have planets in ‘habitable zones,’ where temperatures could support life as we know it.

‘So one of the three big uncertainties has now been constrained.’ He said.

Frank went on to say that the third big question is. how long civilizations might survive – something which is as of yet still completely unknown.

‘The fact that humans have had rudimentary technology for roughly ten thousand years doesn’t really tell us if other societies would last that long or perhaps much longer,’ he explained.

The Drake equation (top row) has proven to be a durable framework for research. But it is impossible to do anything more than guess at variables such as L, the probably longevity of other advanced civilizations. In new research, Adam Frank and Woodruff Sullivan offer a new equation (bottom row)

But Frank and his co-author, Woodruff Sullivan of the astronomy department at the University of Washington, found they could eliminate that term altogether by simply expanding the question.

‘Rather than asking how many civilizations may exist now, we ask ‘are we the only technological species that has ever arisen?’ said Sullivan.

‘This shifted focus eliminates the uncertainty of the civilization lifetime question and allows us to address what we call the ‘cosmic archaeological question’ – how often in the history of the universe has life evolved to an advanced state?

Rather than guessing at the odds of advanced life developing, they calculate the odds against it occurring in order for humanity to be the only advanced civilization.

With that, Frank and Sullivan then calculated the line between a universe where humanity has been the sole experiment in civilization and one where others have come before us.

‘Of course, we have no idea how likely it is that an intelligent technological species will evolve on a given habitable planet,’ says Frank.

‘But using our method we can tell exactly how low that probability would have to be for us to be the only civilization the universe has produced.

‘We call that the pessimism line. If the actual probability is greater than the pessimism line, then a technological species and civilization has likely happened before.’

Using this interesting approach, Frank and Sullivan can now calculate how unlikely advanced life must be if there has never been another example among the universe’s ten billion trillion stars, or even among our own Milky Way galaxy’s hundred billion.

‘One in 10 billion trillion is incredibly small,’ says Frank. ‘To me, this implies that other intelligent, technology producing species very likely have evolved before us.

‘Think of it this way. Before our result you’d be considered a pessimist if you imagined the probability of evolving a civilization on a habitable planet were, say, one in a trillion

‘But even that guess, one chance in a trillion, implies that what has happened here on Earth with humanity has in fact happened about a 10 billion other times over cosmic history.’

Alien Vintage

For smaller volumes the numbers are less extreme.

For example, another technological species likely has evolved on a habitable planet in our own Milky Way galaxy if the odds against it are better than one chance in 60 billion.

But if those numbers seem to give ammunition to the ‘optimists’ about the existence of alien civilizations,

Sullivan points out that the full Drake equation – which calculates the odds that other civilizations are around today – may give solace to the pessimists.

‘The universe is more than 13 billion years old,’ said Sullivan.

‘That means that even if there have been a thousand civilizations in our own galaxy, if they live only as long as we have been around – roughly ten thousand years – then all of them are likely already extinct.

‘And others won’t evolve until we are long gone. For us to have much chance of success in finding another ‘contemporary’ active technological civilization, on average they must last much longer than our present lifetime.’

‘Given the vast distances between stars and the fixed speed of light we might never really be able to have a conversation with another civilization anyway,’ said Frank.

‘If they were 20,000 light years away then every exchange would take 40,000 years to go back and forth.’

But, as Frank and Sullivan point out, even if there aren’t other civilizations in our galaxy to communicate with now, the new result still has a profound scientific and philosophical importance.

‘From a fundamental perspective the question is ‘has it ever happened anywhere before?” said Frank.

Our result is the first time anyone has been able to set any empirical answer for that question and it is astonishingly likely that we are not the only time and place that an advance civilization has evolved.’

Their new equation includes recent data from Nasa’s Kepler satellite on the number of exoplanets that could harbour life. Pictured is an artist’s impression of the probe

U.I.P SUMMARY

Once upon a time leading Scientists wanted us all to believe that we are alone in the Universe – this has now been proven to be pretty much impossible. The Universe is infested with life out there, and we the Human Race are probably far less developed than many older/wiser advanced Alien species.

You will notice that these Scientists nearly always play down their investigations into Alien life, but we mustn’t be too harsh on them for this as they are scared about disclosing too much after so many leading Scientists have recently been killed off (so it appears).

Please check out some previous articles on this subject matter:

Lets not forget that NASA have PROMISED To discover aliens by 2015……!?

MWV